System and method for machine axis coordination for ultrasonic inspection

Abstract

A through-transmission ultrasonic (TTU) inspection system for ultrasonic inspection of a part and for determining alignment calibration data for increased alignment accuracy. The TTU inspection system may include first and second end effectors located on opposite sides of the part, each having at least one transducer for transmitting or receiving ultrasonic or sound waves through the part. The TTU inspection system may also include actuators and a system controller. The system controller may command the actuators to actuate the first end effector according to one or more scanning patterns, while the transducers send and/or receive signals to or from each other through the part. The system controller may use signal strength measurements received along these scanning patterns to determine alignment calibration data for applying to the first end effector and/or its associated actuators.

Having thus described various embodiments of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following: 
     
       1. An ultrasonic inspection system for ultrasonic inspection of a part, the system comprising:
 a first end effector having at least one transducer configured to transmit or receive ultrasonic or sound waves through the part; and 
 a second end effector having at least one transducer configured to transmit or receive ultrasonic or sound waves through the part; 
 actuators configured to receive commands for actuating the first end effector and the second end effector; and 
 a system controller comprising a processor configured for determining alignment calibration data for at least one of the first end effector and the second end effector while the first and second end effectors are located on opposite sides of the part, and configured for outputting command signals to the actuators for actuating the at least one of the first end effector and the second end effector according to the determined alignment calibration data, 
 wherein the system controller is further configured for sending signals to one of the actuators to actuate the first end effector according to a first scanning pattern within a predetermined work envelope, starting at a first location or orientation, while the first end effector transmits or receives ultrasonic or sound waves and the second end effector receives or transmits ultrasonic sound waves at each point along the first scanning pattern, 
 wherein the system controller is further configured to calculate a best alignment position A based on a location or orientation of the first end effector at which signal strength received or sent by the second end effector was strongest along the first scanning pattern that started at the first location or orientation. 
 
     
     
       2. The system of  claim 1 , wherein the system controller is further configured for sending signals to one of the actuators to actuate the first end effector according to a first scanning pattern within the predetermined work envelope, starting at a second location or orientation, while the first end effector transmits or receives ultrasonic or sound waves and the second end effector receives or transmits ultrasonic sound waves at each point along the first scanning pattern. 
     
     
       3. The system of  claim 2 , wherein the system controller is further configured to calculate a best alignment position B based on a location or orientation of the first end effector at which signal strength received or sent by the second end effector was strongest along the first scanning pattern that started at the second location or orientation. 
     
     
       4. The system of  claim 3 , wherein the system controller is further configured for computing, using best alignment position A and best alignment position B, a transformation throughout the predetermined work envelope and applying this transformation as the alignment calibration data for the first end effector to maintain alignment of the first end effector and the second end effector while conducting ultrasonic inspection of the part. 
     
     
       5. The system of  claim 1 , further comprising support components configured for fixing the second end effector to the part in estimated alignment with the first end effector at the first location or orientation. 
     
     
       6. The system of  claim 1 , wherein the system controller is further configured to start a second scanning pattern:
 at a current location or orientation if a current signal sent or received by the first end effector at the current location is greater than a threshold amount more than a previous signal sent or received at a previous location or orientation, 
 at a location or orientation along the first scanning pattern at which signal strength received or sent by the second end effector was strongest, or 
 at the current location or orientation if the current signal sent or received by the first end effector at the current location exceeds a threshold signal strength. 
 
     
     
       7. The system of  claim 6 , wherein the second scanning pattern runs at a lower speed, makes tighter turns, or runs at a higher resolution than the first scanning pattern. 
     
     
       8. A computer-implemented method for properly aligning through-transmission ultrasonic (TTU) inspection system first and second end effectors while located on opposite sides of a part to be inspected, wherein the first and second end effectors each comprise at least one transducer configured to transmit or receive ultrasonic or sound waves through the part, the method comprising the steps of:
 actuating the first end effector according to a first scanning pattern within a predetermined work envelope, starting at a first location or orientation, while the first end effector transmits or receives ultrasonic or sound waves and the second end effector receives or transmits ultrasonic sound waves at each point along the first scanning pattern; 
 determining a best alignment position A based on a location or orientation of the first end effector at which signal strength received or sent by the second end effector was strongest along the first scanning pattern that started at the first location or orientation; 
 moving the first end effector and the second end effector to a second starting location or orientation on opposite sides of the part; 
 actuating the first end effector according to a first scanning pattern within the predetermined work envelope, starting at the second location or orientation, while the first end effector transmits or receives ultrasonic or sound waves and the second end effector receives or transmits ultrasonic sound waves at each point along the first scanning pattern; 
 determining a best alignment position B based on a location or orientation of the first end effector at which signal strength received or sent by the second end effector was strongest along the first scanning pattern that started at the second location or orientation; 
 computing a transformation using best alignment position A and best alignment position B throughout the predetermined work envelope; and 
 applying the transformation as alignment calibration data for the first end effector to maintain accurate alignment of the first end effector and the second end effector while conducting ultrasonic inspection of the part. 
 
     
     
       9. The method of  claim 8 , further comprising a step of fixing the second end effector to the part in an estimated alignment with the first end effector at the first location or orientation. 
     
     
       10. The computer-implemented method of  claim 8 , further comprising a step of starting a second scanning pattern:
 at a current location or orientation if a current signal sent or received by the first end effector at the current location is greater than a threshold amount more than a previous signal sent or received at a previous location or orientation, 
 at a location or orientation along the first scanning pattern at which signal strength received or sent by the second end effector was strongest, or 
 at the current location or orientation if the current signal sent or received by the first end effector at the current location exceeds a threshold signal strength. 
 
     
     
       11. The computer-implemented method of  claim 10 , wherein the second scanning pattern runs at a lower speed, makes tighter turns, or runs at a higher resolution than the first scanning pattern. 
     
     
       12. The computer-implemented method of  claim 8 , further comprising applying a translation to the first end effector at the second location or orientation, wherein the translation is based on the best alignment position A, improving starting position accuracy of the second location or orientation. 
     
     
       13. The computer-implemented method of  claim 8 , wherein at least one of the best alignment position A and the best alignment position B are calculated as a center of mass type equation or based on a weighted average of signal strengths. 
     
     
       14. A physical, non-transitory computer-readable medium with an executable program stored thereon for properly aligning first and second end effectors of a through-transmission ultrasonic (TTU) inspection system while the first and second end effectors are located on opposite sides of a part to be inspected, wherein the first and second end effectors each comprise at least one transducer configured to transmit or receive ultrasonic or sound waves through the part, the program comprising:
 a code segment for commanding actuation of the first end effector according to a first scanning pattern within a predetermined work envelope, starting at a first location or orientation, while the first end effector transmits or receives ultrasonic or sound waves and the second end effector remains stationary and receives or transmits ultrasonic sound waves at each point visited by the first end effector along the first scanning pattern; 
 a code segment for determining a best alignment position A based on a location or orientation of the first end effector at which signal strength received or sent by the second end effector was strongest along the first scanning pattern that started at the first location or orientation; 
 a code segment for moving the first end effector and the second end effector to a second starting location or orientation on opposite sides of the part; 
 a code segment for commanding actuation of the first end effector according to a first scanning pattern within the predetermined work envelope, starting at the second location or orientation, while the first end effector transmits or receives ultrasonic or sound waves and the second end effector remains stationary and receives or transmits ultrasonic sound waves at each point visited by the first end effector along the first scanning pattern; 
 a code segment for determining a best alignment position B based on a location or orientation of the first end effector at which signal strength received or sent by the second end effector was strongest along the first scanning pattern that started at the second location or orientation; 
 a code segment for computing a transformation using best alignment position A and best alignment position B throughout the predetermined work envelope; and 
 a code segment for applying the transformation as alignment calibration data for the first end effector, or actuators associated with the first end effector, to maintain accurate alignment of the first end effector and the second end effector while conducting ultrasonic inspection of the part. 
 
     
     
       15. The program of  claim 14 , further comprising a code segment for starting a second scanning pattern:
 at a current location or orientation if a current signal sent or received by the first end effector at the current location is greater than a threshold amount more than a previous signal sent or received at a previous location or orientation, 
 at a location or orientation along the first scanning pattern at which signal strength received or sent by the second end effector was strongest, or 
 at the current location or orientation if the current signal sent or received by the first end effector at the current location exceeds a threshold signal strength. 
 
     
     
       16. The program of  claim 15 , wherein the second scanning pattern is programmed to run at a lower speed, make tighter turns, or run at a higher resolution than the first scanning pattern. 
     
     
       17. The program of  claim 14 , further comprising a code segment for applying a translation to actuators associated with the first end effector at the second location or orientation, wherein the translation is based on the best alignment position A, thereby improving starting position accuracy of the second location or orientation. 
     
     
       18. The program of  claim 14 , wherein at least one of the best alignment position A and the best alignment position B are calculated as a center of mass type equation or based on a weighted average of signal strengths. 
     
     
       19. An ultrasonic inspection system for ultrasonic inspection of a part, the system comprising:
 a first end effector having at least one transducer configured to transmit or receive ultrasonic or sound waves through the part; and 
 a second end effector having at least one transducer configured to transmit or receive ultrasonic or sound waves through the part; 
 actuators configured to receive commands for actuating the first end effector and the second end effector; and 
 a system controller comprising a processor configured for determining alignment calibration data for at least one of the first end effector and the second end effector while the first and second end effectors are located on opposite sides of the part, and configured for outputting command signals to the actuators for actuating the at least one of the first end effector and the second end effector according to the determined alignment calibration data, 
 wherein the system controller is further configured for sending signals to one of the actuators to actuate the first end effector according to a first scanning pattern within a predetermined work envelope, starting at a first location or orientation, while the first end effector transmits or receives ultrasonic or sound waves and the second end effector receives or transmits ultrasonic sound waves at each point along the first scanning pattern, 
 wherein the system controller is further configured to start a second scanning pattern:
 at a current location or orientation if a current signal sent or received by the first end effector at the current location is greater than a threshold amount more than a previous signal sent or received at a previous location or orientation, 
 at a location or orientation along the first scanning pattern at which signal strength received or sent by the second end effector was strongest, or 
 at the current location or orientation if the current signal sent or received by the first end effector at the current location exceeds a threshold signal strength. 
 
 
     
     
       20. The system of  claim 19 , wherein the second scanning pattern runs at a lower speed, makes tighter turns, or runs at a higher resolution than the first scanning pattern.